Reclassification of a cohort of patients with pituitary neuroendocrine tumors: importance in the prediction of recurrence and/or tumor progression

Abstract

Pituitary neuroendocrine tumors (PitNETs) represent 15% of intracranial tumors. The early recognition of tumors that will have an aggressive behavior, is one of the therapeutic challenges to decide which group of patients need more intensive treatment. According to this, Trouillas et al. proposed a "clinical-pathological-prognostic" classification, which integrates radiological, clinical, and immunocytological data and delineates 5 groups of tumors: "1a" (non-invasive/non-proliferative), "1b" (non-invasive/proliferative), "2a" (invasive/non-proliferative), "2b" (invasive/proliferative) and "3" (carcinoma), demonstrating utility to evaluate the prognosis of patients with aggressive tumors and predicting the risk of recurrence of PitNETs. General Aim: To determine the usefulness of the clinical-pathological-prognostic classification, to predict prognosis, in a cohort of patients with PitNETs.

An observational, analytical, retrospective and longitudinal study. 52 patients who underwent surgery between 2015-2020 were included. Pre/postoperative pituitary resonance, Ki-67 value, mitotic index, p53 expression and postoperative evolution were analyzed. Corresponding statistical tests were used. p<0.05 was considered significant.

53.8% of the patients were women and the mean age was 50 years. A total of 26 patients obtained enough data to be able to re-classify them. The 65.4% correspond to grade "2a", 19.2% to grade "2b", and 15.4% to grade "1a". There were no patients in grades "1b" or "3". Regarding the evolution, 73% showed "Persistence" of the disease, of which 79% correspond to grade 2a and 21% to grade 2b. The rest of the patients demonstrated "Complete Remission" of the disease, with the same distribution (50%) for grades 1a and 2a.

Our results showed the usefulness of the clinical-pathological-prognostic classification to identify a more aggressive subgroup of PitNETs (grade 2b) with a higher risk of progression/ recurrence after initial surgery, because all of them evidenced "persistence" of disease, and it could be beneficial in clinical practice to optimize patient follow-up, preventing complications in this risk population.